The study was carried out to evaluate the effects of complete replacement of maize with two varieties of guinea corn and two varieties of millets on the growth performance and nutrient retention in broiler chickens. Five isonitrogenous and isocaloric diets for the broiler starter (23.5% CP; 2800 kcal/ME) and finisher (21.5% CP; 2900 kcal/ME) phases were formulated. Diet 1 consisted on a maize based diet and it served as the control while diets 2, 3, 4 and 5 were white guinea corn, yellow guinea corn, pearl millet and finger millet based diets, respectively. A total of 225 day old Marshal broiler chickens were randomly assigned to the five experimental diets. Each treatment consisted of 45 birds and 3 replicates of 15 birds each in a completely randomized design. Final body weight (BW) and daily body weight gain (BWG) were higher (P<0.05) in birds fed pearl and finger millet diets at the starter and finisher phases. Pearl millet based diet recorded the best (P<0.05) feed conversion ratio (FCR) and the lowest (P<0.05) feed cost per unit of BWG. Feed intake (FI) at the starter phase was higher in birds fed yellow guinea corn diet than in those fed maize diet. Birds fed white guinea corn diet showed the lowest (P<0.05) BW, BWG, FI and FCR at the finisher phase. To conclude, complete replacement of maize with millets or with yellow guinea corn in broilers diet did not impair FI, BW, FCR and nutrient retention.